One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant periwinkles in Glencoe should be figured out by reviewing the USDA zone info.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since periwinkles require warm weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Glencoe is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant periwinkles and expect a good harvest is probably August. If you wait any later than that and your periwinkles may not have a chance to grow to maturity. If you are starting your periwinkles indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Glencoe the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that USDA zone info for Glencoe may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Glencoe there is a last frost after May 15 be ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Glencoe

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Glencoe

You may be interested in your other planting guides for Glencoe.